Subclinical mastitis causative agents and evaluation of treatment effectiveness with garlic extract (Allicin) in dairy cattle

Objectives: In dairy cattle herds, subclinical mastitis is much more common than clinical mastitis. Farms frequently aren’t aware that some of their milking cows have subclinical mastitis since there aren’t any obvious changes in the milk. Mastitis can be caused by over 140 different types of pathogens that can be found in the cow’s environment. The treatment of subclinical mastitis can often be managed without antibiotics, using non­ steroidal anti- -inflammatory drugs and supportive measures. The aim of the study was to evaluate the treatment effectiveness of subclinical mastitis caused by various pathogens using non- -steroidal anti­ inflammatory drugs and allicin boluses. Methods: The study was conducted on a farm in Lithuania that holds 550 dairy cows. Ten cows with subclinical mastitis were selected for the study. Increased electrical conductivity of the milk, decreased milk production, an increase in the number of somatic cells in the milk, and a positive California Mastitis Test (CMT) result were all used to diagnose subclinical mastitis. Milk samples were taken on the day of diagnosis of subclinical mastitis to identify the causative agent. All cows diagnosed with subclinical mastitis were treated once on the day of diagnosis with Allicin (SCC­ Bolus) 1 unit orally and with karprofen (Rimadyl Cattle 50 mg/ml) at a dosage of 1 ml per 35 kg subcutaneously. After 7 days, microbiological testing of milk was repeated on the same 10 cows to determine if they had recovered. Results: After conducting microbiological tests on the milk, it was found that 5 cows were suffering from mastitis caused by Staphylococcus aureus, 3 by Streptococcus spp., 1 by E. coli, and 1 by Bacillus spp. After re­ evaluating the CMT after 7 days, a positive result was obtained for 3 cows. On the same day, milk samples were taken from all the cows in the study for microbiological testing. Mastitis pathogens were still found in the milk of the 3 cows that tested positive for CMT: one cow had Staphylococcus aureus, and two had Streptococcus spp. pathogens. The treatment was effective for 7 out of the 10 cows. Conclusions: The study used too few cows, so the results were not statistically reliable. It would be beneficial to include more cows in similar studies in the future. However, this study showed that the most common causative agents of subclinical mastitis on one farm in Lithuania are Staphylococcus spp. and Streptococcus spp. The study demonstrated that subclinical mastitis in dairy cows can be effectively treated using non­ steroidal anti- -inflammatory drugs and allicin boluses. With a treatment success rate of 70 %, the combination therapy proved to be beneficial, as evidenced by the resolution of infection in 7 out of the 10 cows assessed.